First off, I totally agree with your conclusion that it's not going to happen. It's an idle threat in the midst of a political back-and-forth. No way that the RCID gets dissolved. No matter how much DeSantis and others wants to rail against Disney, Florida needs Disney, and they are not going to go that far.
However, I would like to see your source for the claim that they have "stated flat-out" that it is due to "being against Disney's 'support' for LGBTQ+ people." I seriously doubt that anyone involved has phrased it that way. That may be your interpretation of it, but I don't think that's what they've "flat-out" said.